CN112055882A

CN112055882A - Photoelectric conversion device, process cartridge, and image forming apparatus

Info

Publication number: CN112055882A
Application number: CN201980026964.4A
Authority: CN
Inventors: 久保大辅; 纸英利; 野副凉佳; 浅野友晴; 利根哲也; 田元望; 田中裕二; 兼为直道
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2018-03-19
Filing date: 2019-01-22
Publication date: 2020-12-08
Also published as: JP7435839B2; US11575095B2; WO2019181176A1; KR20200131293A; EP3769327A1; US20210003931A1; JP2023041717A

Abstract

Provided is a photoelectric conversion device including: a carrier; a charge transport layer comprising an organic charge transport material or a sensitizing dye electrode layer comprising an organic sensitizing dye, wherein the charge transport layer or the sensitizing dye electrode layer is disposed on a support; and a ceramic film disposed on the charge transport layer or the sensitized dye electrode layer.

Description

Photoelectric conversion device, process cartridge, and image forming apparatus

Technical Field

The present disclosure relates to a photoelectric conversion device, a process cartridge, and an image forming apparatus.

Background

In recent years, photoelectric conversion devices including organic semiconductors have been developed and have become available in the market.

At present, most of the widely used photoelectric conversion devices, such as electrophotographic photoconductors, are photoelectric conversion devices formed of an organic material. Problems with such electrophotographic photoconductors formed of organic materials are: as charging and charge elimination are repeatedly performed using an electrophotographic photoconductor, an organic material gradually deteriorates due to electrostatic hazard, thereby generating charge traps within a layer, or changes charging characteristics or light attenuation, thereby degrading electrical characteristics of the electrophotographic photoconductor.

In addition, dye-sensitized solar cells each including an organic sensitizing dye have been developed as organic solar cells whose cost is lower than that of silicon-based solar cells.

However, since the dye-sensitized solar cell includes an organic sensitizing dye as an organic material, the material used is deteriorated by temperature, humidity, or gases such as ozone, NOx, and ammonia gas, as compared to a silicon-based solar cell. As a result, the function thereof tends to be lowered. Therefore, the dye-sensitized solar cell has the following problems: the dye-sensitized solar cell is inferior to a silicon-based solar cell in terms of durability.

In display elements such as organic Electroluminescence (EL) elements, light emitting diode display elements, liquid crystal display elements, electrophoretic ink display elements, and the like, display elements such as an organic EL light emitting layer sandwiched between a positive electrode and a negative electrode are arranged and formed on a substrate. The organic EL display device is expected to be a next-generation display device because the organic EL display device has a wider viewing angle and a faster response speed than a liquid crystal display device, and there are a variety of light-emitting organic materials.

As a forming method of the above-described organic EL element, a forming method using a coating layer has been used in view of productivity and cost. Further, the organic EL element has the following problems: the organic EL element tends to deteriorate due to exposure to heat, moisture, or gas such as oxygen, and thus the service life of the organic EL element becomes short.

As an electrophotographic photoconductor having excellent abrasion resistance and stability of image properties, for example, PTL1 discloses an electrophotographic photoconductor in which a particulate ceramic serving as p-type semiconductor particles is included in a protective layer.

For example, PTL2 discloses, in addition, that an electrophotographic photoconductor has high sensitivity to an exposure light source of a short wavelength region, wherein the electrophotographic photoconductor includes a charge generation layer formed of a metal oxide containing nitrogen, and the charge generation layer is disposed on a support having conductivity in a surface layer thereof.

For example, further, PTL3 discloses a production method of a compound semiconductor film, wherein the production method includes a film formation step including forming the compound semiconductor film on a substrate by an aerosol deposition method.

CITATION LIST

Patent document

[ PTL1] Japanese unexamined patent application publication No. 2015-141269

[ PTL2] Japanese unexamined patent application publication No. 2008-

[ PTL3] Japanese unexamined patent application publication No. 2011-

Disclosure of Invention

Technical problem

An object of the present disclosure is to provide a photoelectric conversion device which is obtained at a low cost and is highly durable without changing its property of withstanding external stimuli such as temperature change, exposure to gas, and humidity change.

Solution to the problem

According to one aspect of the present disclosure, a photoelectric conversion device includes a support, a charge transport layer including an organic charge transport material or a sensitizing dye electrode layer including an organic sensitizing dye, and a ceramic film. A charge transport layer or a sensitized dye electrode layer is disposed on the support. The ceramic membrane is disposed on the charge transport layer or the sensitized dye electrode layer.

Advantageous effects of the invention

The present disclosure can provide a photoelectric conversion device that is obtained at a lower cost and is highly durable without changing its property of withstanding external stimuli such as temperature change, exposure to gas, humidity change, and the like.

Drawings

Fig. 1 is a schematic configuration diagram showing one example of an image forming apparatus of the present disclosure.

Fig. 2 is a schematic configuration diagram showing another example of the image forming apparatus of the present disclosure.

Fig. 3 is a schematic view showing a structure of one example of an image forming unit for each color.

Fig. 4 is a schematic structural view showing one example of the process cartridge of the present disclosure.

Fig. 5 is a cross-sectional view showing one example of a photoelectric conversion apparatus (electrophotographic photoconductor) of the present disclosure.

Fig. 6 is a cross-sectional view showing one example of a photoelectric conversion device (solar cell) of the present disclosure.

Fig. 7 is a cross-sectional view showing one example of a photoelectric conversion apparatus (organic EL element) of the present disclosure.

Fig. 8 is a schematic structural view showing one example of an aerosol deposition device used when forming the ceramic membrane of the present disclosure.

Fig. 9 is a graph depicting one example of the measurement results of the X-ray diffraction spectrum of copper aluminum oxide.

Detailed Description

(photoelectric conversion device)

The photoelectric conversion apparatus of the present disclosure includes a carrier; a charge transport layer comprising an organic charge transport material or a sensitizing dye electrode layer comprising an organic sensitizing dye, wherein the charge transport layer or sensitizing dye electrode layer is disposed on a support; and a ceramic film disposed on the charge transport layer or the sensitized dye electrode layer.

The photoelectric conversion device is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the photoelectric conversion device include devices such as an electrophotographic photoconductor, a solar cell, an organic Electroluminescence (EL) element, a transistor, an integrated circuit, a laser diode, a light emitting diode, and the like.

The photoelectric conversion device of the present disclosure is completed by finding the following problems existing in the art and finding that the photoelectric conversion device of the present disclosure can solve these problems.

Attempts have been made to reduce image defects caused by long-term use of electrophotographic photoconductors as photoelectric conversion devices, and many developments have been reported in association with extending the service life of electrophotographic photoconductors. In order to achieve an extension in the service life of an electrophotographic photoconductor, it is important to improve the durability of the electrophotographic photoconductor to resist various hazards to which the electrophotographic photoconductor is subjected during image formation.

Hazards are broadly divided into mechanical and chemical hazards.

As an example of the chemical hazard, a hazard caused by an acidic gas or an alkaline gas generated when the surface of an electrophotographic photoconductor is charged and an electric charge is applied is known. Acid gases such as ozone, nitrogen, and oxides are generated in the vicinity of the charger (see, for example, j. imaging Science vol.5,205(1988)), and when the electrophotographic photoconductor is exposed to the acid gases, charge transport materials (for example, hole transport materials and electron transport materials) contained in the electrophotographic photoconductor are deteriorated by the acid gases (see, for example, KONICA techincal REPORT vol.13(2000) "underflue of nitrogen oxide over resolution OPC of"), and thus the properties of the electrophotographic photoconductor are impaired. When an electrophotographic photoconductor having a short service life is used, deterioration caused by an acid gas generally occurs only in the outermost surface layer of the electrophotographic photoconductor and the amount of deterioration components is required to be small. When an electrophotographic photoconductor having a long service life is used, however, deterioration may reach internal components of the electrophotographic photoconductor. As a result, image density reduction or background smear may occur, and thus high quality image output cannot be maintained over a long period of use.

In order to solve the problems associated with the chemical hazards, a technique has been proposed in which an antioxidant is added to a charge transport layer or a surface layer to prevent deterioration of a charge transport material due to an acidic gas. Further, in order to prevent the acid gas from permeating the charge transport layer or the surface layer, a technique of reducing the gas permeability of the charge transport layer or the surface layer is proposed. Further, a technique of preventing generation of discharge products (acid gases) during the charging step is proposed.

However, even when the proposed technique is used, a relatively large amount of oxidized and deteriorated components are contained in the electrophotographic photoconductor, and therefore, if the electrophotographic photoconductor is used for a long period of time, fundamental improvement cannot be expected and high-quality output cannot be maintained.

The present disclosure may provide a photoelectric conversion device including a ceramic film disposed on a charge transport layer or a sensitized dye electrode layer including an organic material, which is less resistant to property changes such as temperature changes, exposure to external stimuli such as changes in gas and humidity, and has low cost and high durability.

The proposal of PTL1 disclosed in the background art includes a protective layer including a ceramic as a p-type semiconductor, but the ceramic is not in the form of a film, but a particulate semiconductor.

The proposals of PTLs 2 to 3 cannot achieve the object of the present disclosure because a structure in which a metal oxide film or a compound semiconductor thin film is disposed on a layer including an organic material is not proposed.

< ceramic film >

The ceramic film is a film formed of ceramic.

Ceramics are generally metal compounds obtained by firing metals. The ceramic is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the ceramic include metal oxides such as titanium oxide, silicon dioxide, aluminum oxide, zirconium oxide, tin oxide, and indium oxide.

The ceramic is preferably a ceramic semiconductor.

The ceramic film is preferably a ceramic semiconductor film.

< ceramic semiconductor >)

Among ceramics, a ceramic semiconductor is a ceramic whose typical electronic configuration is partially defective due to oxygen deficiency, and is a generic term of a compound that exhibits conductivity under specific conditions due to the defect of the electronic configuration.

The ceramic semiconductor film has the following characteristics: the ceramic semiconductor film exhibits conductivity under specific conditions, is a layer in which ceramic semiconductor components are densely arranged without any gap, and is a layer not including an organic compound. The ceramic semiconductor film preferably comprises delafossite.

Further, in the present disclosure, in view of application to a photoelectric conversion device, the ceramic semiconductor film preferably has charge mobility of holes or electrons.

In addition, the magnetic field intensity is 2 x 10⁵The charge mobility of the ceramic semiconductor in the case of V/cm is preferably 1X 10^- ⁶cm²a/Vsec or greater. In the present disclosure, the higher the charge mobility, the better.

The measurement method of the charge mobility is not particularly limited, and may be appropriately selected from general measurement methods as needed. Examples of the measurement method include a method in which production and measurement of a sample are performed according to the method disclosed in japanese unexamined patent application publication No. 2010-183072.

Further, the bulk resistance of the ceramic semiconductor film including the thickness thereof is preferably less than 1 × 10¹³ohm。

Delafossite-

The delafossite (hereinafter may be referred to as "p-type semiconductor" or "p-type metal compound semiconductor") is not particularly limited as long as the delafossite has a function as a p-type semiconductor, and may be appropriately selected depending on the intended purpose. Examples of delafossite include p-type metal oxide semiconductors, p-type compound semiconductors including monovalent copper, and other p-type metal compound semiconductors.

Examples of p-type metal oxide semiconductors include CoO, NiO, FeO, Bi₂O₃、MoO₂、MoS₂、Cr₂O₃、SrCu₂O₂And CaO-Al₂O₃。

Examples of the p-type compound semiconductor including monovalent copper include CuI, CuInSe₂、Cu₂O、CuSCN、CuS、CuInS₂、CuAlO、CuAlO₂、CuAlSe₂、CuGaO₂、CuGaS₂And CuGaSe₂。

Examples of other p-type metal compound semiconductors include GaP, GaAs, Si, Ge, and SiC.

(production of ceramic film)

The production method (film forming method) of the ceramic film is not particularly limited, and may be appropriately selected from film forming methods of inorganic materials generally used according to the intended purpose. Examples of the production method include a vapor deposition method, a liquid phase growth method, and a solid phase growth method.

For example, the vapor deposition method is classified into a Physical Vapor Deposition (PVD) method and a Chemical Vapor Deposition (CVD) method.

Examples of physical vapor deposition methods include vacuum vapor deposition, electron beam vapor deposition, laser abrasion MBE, MOMBE, reactive vapor deposition, ion plating, cluster ion beam method, glow discharge sputtering, ion beam sputtering, and reactive sputtering.

Examples of the chemical vapor deposition method include thermal CVD, MOCVD, RF plasma CVD, ECR plasma CVD, optical CVD, and laser CVD.

Examples of the liquid phase growth method include LPE, electroplating, electroless plating, and coating.

Examples of the solid phase growth method include SPE, recrystallization method, graphoepitaxix (graphoepitaxix), LB method, sol-gel method, and Aerosol Deposition (AD) method.

Among the above-listed methods, the AD method is preferable because a uniform film is formed over a relatively large area such as an electrophotographic photoconductor, or the properties of the electrophotographic photoconductor are not affected by the production method.

Aerosol Deposition (AD) method

The Aerosol Deposition (AD) method is a technique in which particles or ultrafine particles prepared in advance are mixed with a gas to form an aerosol and the aerosol is sprayed onto a film-forming target (substrate) to form a coating film.

As a characteristic of the AD method, film formation may be performed in a room temperature environment and may be performed in a state in which the crystal structure of the raw material is almost maintained. Therefore, the AD method is suitably used for film formation on a photoelectric conversion device (particularly, an electrophotographic photoconductor).

A method of forming a ceramic film according to the aerosol deposition method will be described.

For the method of forming the ceramic film, an aerosol deposition apparatus shown in fig. 8 was used. In the gas cylinder 11 shown in fig. 8, an inert gas for generating aerosol is stored. The gas cylinder 11 is coupled with the aerosol generator 13 via a pipe 12a, and the pipe 12a is introduced into the aerosol generator 13. The aerosol generator 13 is filled with a quantity of particles 20 formed of a metal oxide or compound semiconductor. Another pipe 12b coupled to the aerosol generator 13 is connected to a nozzle 15 in the film forming chamber 14.

In the film forming chamber 14, the substrate 16 is held by a substrate holder 17 in such a manner that the substrate 16 faces the nozzle 15. An aluminum foil (positive electrode current collector) was used as the substrate 16. An exhaust pump 18 is connected to the film forming chamber 14 via a pipe 12c, wherein the exhaust pump 18 is configured to adjust the degree of vacuum within the film forming chamber 14.

Although not shown, the film formation device configured to form the electrode of the present embodiment includes such a system: the system moves the substrate holder 17 in a lateral direction (lateral direction on the plane of the substrate holder 17 facing the nozzle 15) and moves the nozzle 15 in a longitudinal direction (longitudinal direction on the plane of the substrate holder 17 facing the nozzle 15) at a constant speed. A ceramic film of a desired area can be formed on the substrate 16 by moving the substrate holder 17 in the lateral direction and moving the nozzle 15 in the longitudinal direction to perform film formation.

In the process for forming a ceramic film, first, the compressed air valve 19 is closed, and the internal atmosphere from the film forming chamber 14 to the aerosol generator 13 is evacuated by the exhaust pump 18. Aerosol is generated in a state where the particles 20 are dispersed in the gas by opening the compressed air valve 19 to introduce the gas in the gas cylinder 11 into the aerosol generator 13 through the pipe 12a to disperse the particles 20 in the container. The generated aerosol is ejected from the nozzle 15 toward the substrate 16 via the nozzle 12b at a high velocity. After 0.5 second has elapsed with the compressed air valve 19 opened, the compressed air valve 19 is closed for the next 0.5 second. Thereafter, the compressed air valve 19 was opened again, and the compressed air valve 19 was opened and closed repeatedly at intervals of 0.5 second. The gas flow rate from the gas cylinder 11 was set to 2L/min, the duration of film formation was 7 hours, the degree of vacuum in the film forming chamber 14 was about 10Pa when the compressed air valve 19 was closed, and the degree of vacuum in the film forming chamber 14 was about 100Pa when the compressed air valve 19 was opened.

The ejection speed of the aerosol is controlled by the shape of the nozzle 15, the length or inner diameter of the pipe 12b, the internal air pressure of the gas cylinder 11, or the displacement of the displacement pump 18 (the internal pressure of the film forming chamber 14). When the internal pressure of the aerosol generator 13 is set to several tens of thousands Pa, the internal pressure of the film forming chamber 14 is set to several hundreds Pa, and the opening shape of the nozzle 15 is a circular shape having an inner diameter of 1mm, for example, the ejection speed of the aerosol may reach several hundreds m/sec due to the internal pressure difference between the aerosol generator 13 and the film forming chamber 14. A ceramic film having a porosity of 5% or more but 30% or less can be formed by maintaining the internal pressure of the film forming chamber 14 at 5Pa or more but 100Pa or less and maintaining the internal pressure of the aerosol generator 13 at 50,000 Pa. By adjusting the duration of the aerosol application under the above conditions, the average thickness of the ceramic membrane is preferably adjusted to 0.1 micron or more but 10 microns or less.

The particles 20 in the aerosol, in which the moving speed of the particles is accelerated to obtain kinetic energy, are made to collide into the substrate 16 and are finely pulverized by collision energy. Then, the pulverized particles bonded to the substrate 16 and the pulverized particles are bonded together to sequentially form a ceramic film on the charge transport layer.

Film formation is performed by forming a line pattern and rotating a photoconductor drum a plurality of times. The drum support 17 or the nozzle 15 is scanned in the longitudinal direction or the transverse direction on the surface of the substrate 16 (current collector 23) to form the positive electrode active material layer 21 of a desired area. The method is as follows. First, the substrate holder 17 is fixed in the longitudinal direction and scanned in the lateral direction at a constant speed. Once the scanning of one line is completed, the nozzle 15 is moved in the longitudinal direction in consideration of overlapping with the previous film formation region, and then the substrate holder 17 is scanned in the transverse direction. As described above, the substrate holder 17 is moved several times in the longitudinal direction until the substrate holder 17 reaches a desired longitudinal position, and scanning in the lateral direction is repeated. As a result, deposition of a desired film formation region can be performed.

(electrophotographic photoconductor)

One embodiment of the photoelectric conversion apparatus of the present disclosure is an electrophotographic photoconductor.

Electrophotographic photoconductors (which may be referred to hereinafter as "photoconductors") include a conductive support that serves as a support, a charge transport layer comprising an organic charge transport material, wherein the charge transport layer is disposed on the support, and a ceramic film disposed on the charge transport layer. The photoelectric conversion device further includes a charge generation layer, and may further include other layers such as an intermediate layer and a protective layer, as necessary.

For the ceramic film, any of the above-mentioned substances can be suitably applied.

Note that a layer obtained by subsequently laminating a charge generation layer and a charge transport layer may be referred to as a photoconductive layer.

An example in which the photoelectric conversion apparatus is an electrophotographic photoconductor will be described hereinafter, but the photoelectric conversion apparatus is not limited to the electrophotographic photoconductor and may be applied to another photoelectric conversion apparatus.

The structure of the photoelectric conversion apparatus 10A as an electrophotographic photoconductor will be described based on fig. 5. Note that fig. 5 is a cross-sectional view showing one example of an electrophotographic photoconductor.

One embodiment of an electrophotographic photoconductor is shown in fig. 5. In the embodiment shown in fig. 5, the electrophotographic photoconductor 10A includes the intermediate layer 2, the charge generation layer 3, the charge transport layer 4, and the ceramic film 5 on the conductive support 1 in this order.

< Carrier (conductive Carrier) >

The conductive carrier is not particularly limited and may be appropriately selected depending on the intended purpose, as long as the conductive carrier has the composition exhibiting 10¹⁰A conductivity of a volume resistivity of ohm cm or less. Examples of the conductive carrier include: a support obtained by vapor deposition or sputtering with a metal (e.g., aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, and iron) or an oxide (e.g., tin oxide and indium oxide) coating film or cylindrical plastic or paper; a plate of aluminum, aluminum alloy, nickel or stainless steel; and a pipe obtained by forming the above plate into a pipe by a method such as drawing and drawing (drawing), impact drawing (impact drawing), extrusion drawing (extruded drawing), or cutting, followed by performing surface treatment such as cutting, superfinishing, and polishing.

< intermediate layer >

An electrophotographic photoconductor may include an intermediate layer disposed between a conductive support and a photoconductive layer. The purpose of the intermediate layer is to improve adhesion, prevent moire, improve coatability of the upper layer, and prevent charge injection from the conductive carrier.

Typically, the intermediate layer includes a resin as a main component. Since the photoconductive layer is coated on the intermediate layer, the resin used in the intermediate layer is preferably a thermosetting resin insoluble in an organic solvent. Among these thermosetting resins, polyurethane, melamine resin and alkyd melamine resin are more preferable because most of these resins fully satisfy the above object.

Examples of the organic solvent include tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, and butanone. The resin may be appropriately diluted with an organic solvent, and the resultant may be used as a coating material.

Furthermore, particles of metal or metal oxide may be added to the intermediate layer in order to control conductivity or prevent moire. The metal oxide is preferably titanium oxide or zinc oxide. The particles are dispersed in an organic solvent by means of a ball mill, an attritor and a sand mill to obtain a dispersion liquid, the dispersion liquid and the resin component are mixed, and the resultant can be used as a coating material.

Examples of the production method (film forming method) of the intermediate layer include: a method in which a coating material is applied to a conductive support by dip coating, spray coating, bead coating, or the like to form a film; and a method in which the obtained film is optionally heated or cured. When the average thickness is about 2 microns or more but about 20 microns or less, the average thickness of the intermediate layer is generally suitable. In the case where the accumulation of the residual potential of the photoconductor is large, the average thickness of the intermediate layer can be made smaller than 3 μm.

< photoconductive layer >

The photoconductive layer of the photoconductor is a laminated photoconductive layer in which a charge generation layer and a charge transport layer are sequentially laminated as the photoconductive layer.

< Charge generation layer >

The charge generation layer is a part of the laminated photoconductive layer, and has a function of generating charges by exposure to light. The charge generating layer includes a charge generating material as a main component, and may further include a binder resin as needed. Examples of the charge generating material include inorganic charge generating materials and organic charge generating materials.

Examples of the inorganic charge generation material include crystalline selenium, amorphous selenium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. As the amorphous silicon, amorphous silicon whose dangling bonds are terminated with hydrogen atoms or halogen atoms, or amorphous silicon doped with boron atoms or phosphorus atoms is preferably used.

As the organic charge generating material, any material known in the art may be used. Examples of the organic charge generating material include metal phthalocyanines (e.g., oxytitanium phthalocyanine and chlorogallium phthalocyanine), nonmetal phthalocyanines, azlenium salt pigments, squarylium methane pigments, symmetric or asymmetric azo pigments having a carbazole skeleton, symmetric or asymmetric azo pigments having a triphenylamine skeleton, symmetric or asymmetric azo pigments having a fluorenone skeleton, and perylene-based pigments. Among the examples listed above, metal phthalocyanines, symmetric or asymmetric azo pigments having a fluorenone skeleton, symmetric or asymmetric azo pigments having a triphenylamine skeleton, and perylene-based pigments are preferable because all of the above materials have higher quantum efficiency of charge generation. The charge generation materials listed above may be used alone or in combination.

Examples of the binder resin include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and polyacrylamide.

In addition, the polymeric charge transport materials described below may also be used. In the examples listed above, polyvinyl butyral is often used and is effective. The above-listed binder resins may be used alone or in combination.

(method for producing Charge generating layer)

The production method of the charge generating layer can be roughly classified into a vacuum thin film forming method and a casting method from a solution dispersion system.

Examples of the vacuum thin film formation method include vacuum vapor deposition, glow discharge decomposition, ion plating, sputtering, reactive sputtering, and Chemical Vapor Deposition (CVD). The vacuum thin film formation method is suitably used for producing a layer formed of an inorganic charge generating material or an organic charge generating material.

As a production method of the charge generation layer by casting, the above-mentioned inorganic charge generation material or organic charge generation material is dispersed in an organic solvent by means of a ball mill, an attritor, or a sand mill optionally together with a binder resin to obtain a dispersion liquid, and the dispersion liquid is appropriately diluted and applied.

Examples of the organic solvent include tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, and butanone. Among the examples listed above, methyl ethyl ketone, tetrahydrofuran and cyclohexanone are preferred because these solvents have a lower degree of environmental load compared to chlorobenzene, dichloromethane, toluene and xylene.

The application of the dispersion may be by dip coating, spray coating or bead coating.

The average thickness of the charge generation layer is preferably 0.01 micrometers or more but 5 micrometers or less.

In the case where it is desired to reduce the residual potential or increase the sensitivity, the above properties are generally improved by increasing the film thickness of the charge generation layer. On the other hand, the increased thickness of the charge generation layer tends to cause deterioration of charging properties such as retention of charge or formation of space charge. In view of the balance between the above advantages and disadvantages, the average thickness of the charge generation layer is more preferably 0.05 micrometers or more but 2 micrometers or less.

In addition, a low molecular weight compound (e.g., an antioxidant, a plasticizer, a lubricant, and a UV absorber) and a leveling agent may be optionally added to the charge generating layer. The above-listed compounds may be used alone or in combination. The combined use of the low molecular weight compound and the leveling agent generally causes deterioration in sensitivity. Therefore, the low molecular weight compound and the leveling agent are generally preferably used in an amount of 0.1phr or more but 20phr or less, and more preferably 0.1phr or more but 10phr or less. The leveling agent is preferably used in an amount of 0.001phr or more but 0.1phr or less.

< Charge transport layer >

The charge transport layer is a part of the laminated photoconductive layer, and has a function of injecting and transporting charges generated in the charge generation layer to neutralize surface charges of the photoconductor generated by charging. The charge transport layer includes a charge transport material as a main component and a binder component configured to bind the charge transport material.

The charge transport layer includes at least an organic charge transport material as the charge transport material. The charge transport layer may further include a low molecular weight electron transport material and a hole transport material as necessary.

Examples of the low-molecular-weight electron transporting material include electron accepting materials such as asymmetric diphenoquinone derivatives, fluorene derivatives, and naphthalimide derivatives. The electron transport materials listed above may be used alone or in combination.

As the hole transport material, an electron donor material is preferably used. Examples of the hole transport material include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, butadiene derivatives, 9- (p-diethylaminostyrylanthracene), 1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylacylhydrazone, α -phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives. The above-listed hole transport materials may be used alone or in combination.

Organic charge transport materials

Examples of the organic charge transport material (which may be hereinafter referred to as "polymeric charge transport material") include polymers containing carbazole rings (e.g., poly-N-vinylcarbazole), polymers having hydrazone, polysilicene polymers, and aromatic polycarbonates. The organic charge transport materials listed above may be used alone or in combination.

The organic charge transport material is a material suitable for preventing curing failure of the crosslinked surface layer because when the crosslinked surface layer is disposed on the crosslinked surface layer, the components constituting the organic charge transport material exude less on the crosslinked surface layer than the low-molecular-weight charge transport material. As the molecular weight of the charge transport material increases, the heat resistance improves more. Therefore, deterioration due to curing heat is less likely to occur at the time of film formation of the crosslinked surface layer, and thus it is advantageous to use an organic charge transport material.

Examples of the binder component include thermoplastic or thermosetting resins such as polystyrene, polyester, polyethylene, polyarylate, polycarbonate, acrylic resin, silicone resin, fluorine resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, and alkyd resin. Among the above listed examples, polystyrene, polyester, polyarylate and polycarbonate are effective because most of the above listed compounds exhibit excellent charge transport properties when they are used as a binder component of a charge transport component. Since the crosslinked surface layer is preferably arranged on the charge transport layer, furthermore, unlike charge transport layers known in the art, the charge transport layer does not need to provide mechanical strength. Therefore, a material having relatively low mechanical strength but high transparency, such as polystyrene, which has been determined to be unsuitable in the related art, can be effectively used as a binder component of the charge transport layer.

The binder component may be used alone or in combination, or as a copolymer formed from two or more of its starting material monomers, or as a copolymer with a charge transport material.

When an electrically inert polymer compound is used to improve the charge transport layer, cardo polymer type polyesters having a large skeleton such as fluorene, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycarbonates in which the 3, 3' -position of the phenol component of bisphenol polycarbonate is substituted with an alkyl group (such as C-type polycarbonate), polycarbonates in which the geminal methyl group of bisphenol a is substituted with a long-chain alkyl group having 2 or more carbon atoms, polycarbonates having a biphenyl or biphenyl ether skeleton, polycaprolactone, polycarbonates including a long-chain alkyl skeleton such as polycaprolactone (disclosed in japanese unexamined patent application publication No. 07-292095, for example), acrylic resins, polystyrene, or hydrogenated butadiene are effective.

The electrically inert polymer compound means a polymer compound that does not contain a chemical structure exhibiting photoconductivity, such as a triarylamine structure. When an electrically inert polymer compound is used as an additive in combination with the binder resin, the amount thereof is preferably 50% by mass with respect to the total solid content of the charge transport layer in view of the limitation of light attenuation sensitivity.

When a low molecular weight charge transport material is used, the amount thereof is generally, preferably 40phr or more but 200phr or less, and more preferably 70phr or more but 100phr or less. When a polymeric charge transport material is used, it is preferable to use a material obtained by copolymerization of a charge transport component and the resin component in an approximate proportion that the amount of the resin component relative to 100 parts by mass of the charge transport component is 0 parts by mass or more but 200 parts by mass or less, preferably 80 parts by mass or more but 150 parts by mass or less.

In view of satisfying high sensitivity, the amount of the charge transport material is preferably 70phr or more. Further, polymeric charge transport materials each having a structure of a monomer, a dimer, or an α -phenyl stilbene compound, a benzidine compound, or a butadiene compound in a main chain or a side chain thereof are generally materials having high charge mobility, and can be effectively used as charge transport materials.

The charge transport layer may be formed by dissolving or dispersing a mixture or copolymer including a charge transport component and a binder component as main components in an appropriate solvent to prepare a charge transport layer coating material, and applying and drying the coating material. As the application method, dipping, spray coating, hoop coating, roll coater method, gravure coating, nozzle coating, or screen coating may be applied.

Examples of dispersing solvents that can be used to prepare the charge transport layer coating material include: ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone; ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve; aromatic hydrocarbons such as toluene and xylene; halogens such as chlorobenzene and dichloromethane; and esters such as ethyl acetate and butyl acetate. Among the examples listed above, methyl ethyl ketone, tetrahydrofuran and cyclohexanone are preferred because they have a lower degree of environmental load than chlorobenzene, dichloromethane, toluene and xylene. The solvents listed above may be used alone or in combination.

Since the crosslinked surface layer is generally disposed above the charge transport layer, the average thickness of the charge transport layer in such a structure need not be made thicker in view of potential film wear in actual use. In order to ensure necessary sensitivity and charging ability in practice, the average thickness of the charge transport layer is preferably 10 micrometers or more but 40 micrometers or less, and more preferably 15 micrometers or more but 30 micrometers or less.

In addition, a low molecular weight compound (e.g., an antioxidant, a plasticizer, a lubricant, and a UV absorber) and a leveling agent may be optionally added to the charge transport layer. The above-listed compounds may be used alone or in combination. The combined use of the low molecular weight compound and the leveling agent generally causes deterioration in sensitivity. Therefore, the low molecular weight compound and the leveling agent are generally preferably used in an amount of 0.1phr or more but 20phr or less, and more preferably 0.1phr or more but 10phr or less, and the leveling agent is used in an amount of approximately about 0.001phr or more but about 0.1phr or less.

< ceramic film >

As the ceramic film in the electrophotographic photoconductor and the production method thereof, the substance in the ceramic film described in relation to the photoelectric conversion device of the present disclosure and the production method thereof can be appropriately selected and applied.

< protective layer (surface layer) >

The protective layer (surface layer) other than the ceramic film is not particularly limited and may be appropriately selected from protective films (surface layers) known in the art.

(image Forming apparatus)

The image forming apparatus of the present disclosure includes an electrophotographic photoconductor (photoelectric conversion device), and further includes a latent electrostatic image forming unit and a developing unit. The image forming apparatus may further include other units as necessary.

An image forming method related to the present disclosure includes at least an electrostatic latent image forming step and a developing step. The image forming method may further include other steps as necessary.

The image forming method is suitably performed by an image forming apparatus. The electrostatic latent image forming step is suitably performed by an electrostatic latent image forming unit. The developing step is suitably performed by a developing unit. The above-mentioned other steps are suitably performed by the above-mentioned other units.

< Electrostatic latent image Forming Unit and Electrostatic latent image Forming step >

The electrostatic latent image forming unit is not particularly limited and may be appropriately selected according to the intended purpose, as long as the electrostatic latent image forming unit is a unit configured to form an electrostatic latent image on an electrostatic latent image bearer. Examples of the latent electrostatic image forming unit include a unit including at least a charging member configured to charge a surface of a latent electrostatic image carrier and an exposure unit configured to imagewise expose the surface of the latent electrostatic image carrier to light.

The electrostatic latent image forming step is not particularly limited and may be appropriately selected according to the intended purpose, as long as the electrostatic latent image forming step is a step including forming an electrostatic latent image on an electrostatic latent image bearer. For example, the electrostatic latent image forming step may be performed by charging the surface of the electrostatic latent image bearer, followed by image-wise exposure, and may be performed by an electrostatic latent image forming unit.

< < charging means and charging >)

The charging member is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the charging member include contact chargers known in the art which are themselves equipped with a conductive or semiconductive roller, a brush, a film, or a rubber blade, and non-contact chargers utilizing corona discharge, such as a corotron and a scorotron.

For example, charging may be performed by applying a voltage to the surface of the electrostatic latent image carrier using a charging member.

< Exposure Member and Exposure >

The exposure member is not particularly limited and may be appropriately selected depending on the intended purpose, as long as the exposure member can imagewise expose the surface of the electrostatic latent image carrier charged by the charging member to light. Examples of the exposure means include various exposure means such as a reproducing optical exposure unit, a rod lens array exposure unit, a laser optical exposure unit, and a liquid crystal shutter optical unit.

For example, exposure may be performed by exposing the surface of the latent electrostatic image carrier to light imagewise using an exposure means.

Note that in the present disclosure, a backlight system that performs exposure from the back surface of the electrostatic latent image carrier in an image-wise manner may be employed.

< developing unit and developing step >

The developing unit is not particularly limited and may be appropriately selected according to the intended purpose, as long as the developing unit is a developing unit that stores toner therein and is configured to develop an electrostatic latent image on an electrostatic latent image carrier with the toner to form a visible image.

The developing step is not particularly limited and may be appropriately selected depending on the intended purpose, as long as the developing step is a step including developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a visible image. For example, the developing step may be performed by a developing unit.

The developing unit may be a dry developing system or a wet developing system. Further, the developing unit may be a developing unit for a single color or a developing unit for a plurality of colors.

The developing unit is preferably a developing device including an agitator configured to agitate toner to charge the toner by friction, and a rotatable developer carrier including a magnetic field generating unit fixed therein and capable of carrying a developer including the toner on a surface thereof.

< other units and other steps >

Examples of the above-described other units include a transfer unit, a fixing unit, a cleaning unit, a charge eliminating unit, a recovery unit, and a control unit.

Examples of the above-mentioned other steps include a transfer step, a fixing step, a cleaning step, a charge eliminating step, a recovering step, and a controlling step.

Next, one embodiment of a method of forming an image using the image forming apparatus of the present disclosure will be described with reference to fig. 1. The image forming apparatus 100A shown in fig. 1 includes a photoconductor drum 10 serving as a latent electrostatic image carrier, a charging roller 20 serving as a charging unit, an exposure device (not shown) serving as an exposure unit, a developing device 45(K, Y, M and C) serving as a developing unit, an intermediate transfer member 50, a cleaning device 6 having a cleaning blade serving as a cleaning unit, and a charge eliminating lamp 70 serving as a charge eliminating unit.

The intermediate transfer member 50 is an endless belt. The intermediate transfer member 50 is supported by 3 rollers 51 arranged inside the intermediate transfer member 50, and is movable in the direction indicated by the arrow. A part of the 3 rollers 51 also functions as a transfer bias roller capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50.

Further, a cleaning device 90 having a cleaning blade is disposed in the vicinity of the intermediate transfer member 50. Further, as a transfer unit configured to apply a transfer bias so as to transfer (secondary transfer) the toner image to the recording paper 95, a transfer roller 80 is disposed facing the intermediate transfer member 50.

In the peripheral area of the intermediate transfer member 50, a corona charger 52 configured to apply an electric charge to the toner image on the intermediate transfer member 50 is disposed at a contact area between the photoconductor drum 10 and the intermediate transfer member 50, and a contact area between the intermediate transfer member 50 and the recording paper 95.

The developing device 45 of each of black (K), yellow (Y), magenta (M), and cyan (C) includes a developer storage unit 42(K, Y, M or C), a developer supply roller 43, and a developing roller 44.

In the image forming apparatus 100A, after the photoconductor drum 10 is uniformly charged by the charging roller 20, the photoconductor drum 10 is imagewise exposed to exposure light L by an exposure device (not shown) to form an electrostatic latent image. Next, a developer is supplied from the developing device 45 to the electrostatic latent image formed on the photoconductor drum 10 to develop and form a toner image. Thereafter, the toner image is transferred (primary transfer) to the intermediate transfer member 50 by a transfer bias applied by the roller 51. After electric charge is applied to the toner image on the intermediate transfer member 50 by the corona charger 52, the toner image is transferred (secondary transfer) to the recording paper 95. Note that the residual toner on the photoconductor drum 10 is removed by the cleaning device 6. The charge of the photoconductor drum 10 is eliminated by the charge eliminating lamp 70.

Another example of the image forming apparatus of the present disclosure is shown in fig. 2. The image forming apparatus 100B is a tandem-type color image forming apparatus, and includes a copier main body 150, a paper feed table 200, a scanner 300, and an Automatic Document Feeder (ADF) 400.

In the center area of the copier main body 150, an endless belt type intermediate transfer member 50 is arranged. The intermediate transfer member 50 is supported by the supporting

rollers

14, 15, and 16, and is rotatable in the direction indicated by the arrow.

A cleaning device 17 configured to remove toner remaining on the intermediate transfer member 50 is disposed in the vicinity of the supporting roller 15. Further, a tandem developing device 120 in which four image forming units 18 of yellow, cyan, magenta, and black are arranged in tandem along the traveling direction of the intermediate transfer member 50 is disposed in the vicinity of the intermediate transfer member 50 supported by the backup roller 14 and the backup roller 15.

As shown in fig. 3, the image forming unit 18 of each color includes a photoconductor drum 10, a charging roller 60 configured to uniformly charge the photoconductor drum 10, a developing device 61 configured to develop an electrostatic latent image formed on the photoconductor drum 10 with a developer of each of black (K), yellow (Y), magenta (M), and cyan (C) to form a toner image, a transfer roller 62 configured to transfer the toner image of each color to the intermediate transfer member 50, a photoconductor cleaning device 63, and a charge eliminating lamp 64. In fig. 3, reference symbol L denotes a laser.

Further, in the image forming apparatus of fig. 2, an exposure device (not shown) is arranged near the tandem developing device 120. The exposure device is configured to expose the photoconductor drum 10 to exposure light to form an electrostatic latent image.

Further, the secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side where the tandem developing device 120 is disposed. The secondary transfer device 22 includes a secondary transfer belt 24, which is an endless belt supported by a pair of rollers 23 and is designed in such a manner that recording papers conveyed on the secondary transfer belt 24 and the intermediate transfer member 50 can contact each other.

The fixing device 25 is disposed near the secondary transfer device 22. The fixing device 2 includes a fixing belt 26 as an endless belt and a pressure roller 27 arranged in such a manner as to press the pressure roller against the fixing belt 26.

Further, a reverser 28 configured to reverse the recording paper to form images on both sides of the recording paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25.

Next, the formation of a full-color image (color copy) performed in the image forming apparatus 100B will be described. First, a document is set on the document table 130 of the Automatic Document Feeder (ADF) 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and then the automatic document feeder 400 is closed. In the case where a document is set on the automatic document feeder 400, the document is transferred onto the contact glass 32 upon pressing a start switch (not shown), and then the scanner 300 is driven to scan the first carriage 33 and the second carriage 34. In the case where a document is set on the contact glass 32, the scanner 300 is immediately driven to scan the first carriage 33 and the second carriage 34. During the scanning operation, light applied from the light source of the first carriage 33 is reflected by the surface of the document, light reflected from the document surface is reflected by the mirror of the second carriage 34, and then the reflected light is received by the reading sensor 36 via the imaging lens 35. As a result, the color document (color image) is read, and image information of each of black, yellow, magenta, and cyan is obtained.

After forming the electrostatic latent images of the above colors on the photoconductor drums 10 based on the obtained images of each color, the electrostatic latent images of each color are developed by the developer supplied from the developing device of each color, thereby forming toner images of each color. The formed toner images of the above colors are sequentially transferred (primary transfer) and superposed on the intermediate transfer member 50 rotatably driven by the supporting

rollers

14, 15, and 16, thereby forming a composite toner image on the intermediate transfer member 50.

In the sheet feeding table 200, one of the sheet feeding rollers 142 is selectively rotated to discharge recording sheets from one or more sheet feeding cassettes 144 of the sheet bank 143, and the sheets of the discharged recording sheets are separated one by a separation roller 145 to convey each sheet of the recording sheets to a sheet feeding path 146 and then to a sheet feeding path 148 in the copying machine main body 150 by a conveying roller 147. Then, the recording paper transported in the paper feed path 148 collides against the registration roller 49 and stops. Alternatively, the sheets of recording paper on the manual feeding tray 54 are discharged and separated one by the separation roller 58 to be guided to the manual feeding path 53, and then stopped by colliding against the registration roller 49. Note that the registration roller 49 is normally grounded when in use, but may be biased when in use so as to remove paper dust of the recording paper.

Then, the registration roller 49 is rotated in synchronization with the movement of the composite toner image formed on the intermediate transfer member 50 to convey the recording paper between the intermediate transfer member 50 and the secondary transfer device 22, thereby transferring (secondary transfer) the composite toner image onto the recording paper.

The recording sheet to which the composite toner image has been transferred is transported by the secondary transfer device 22 to convey the recording sheet to the fixing device 25. Then, the composite toner image is heated and pressed by a fixing belt 26 and a pressing roller 27 in the fixing device 25 to fix the composite toner image on the recording paper. Thereafter, the traveling path of the recording paper is switched by the switching crawler 55 and discharged and stacked on the discharge tray 57 by the discharge rollers 56. Alternatively, the traveling path of the recording paper is switched by the switching crawler 55, and the recording paper is reversed by the reverser 28 to convey the recording paper to the transfer position again. After an image is formed on the back side of the recording paper, the recording paper is discharged by the discharge rollers 56 and stacked on the paper discharge tray 57.

Note that the toner remaining on the intermediate transfer member 50 after the transfer of the composite toner image is removed by the cleaning device 17.

(processing box)

The process cartridge of the present disclosure includes an electrophotographic photoconductor (photoelectric conversion device), and further includes a developing unit configured to develop an electrostatic latent image on the electrophotographic photoconductor with toner to form a toner image. The process cartridge may further include other units as necessary.

The process cartridge is configured in such a manner that the process cartridge is detachably mounted in various image forming apparatuses.

The developing unit includes a toner storage unit configured to store toner thereon and a toner carrier configured to carry and transport the toner stored in the toner storage unit. Note that the developing unit may further include a regulator member configured to regulate a thickness of the toner carried on the toner carrier.

One example of a process cartridge associated with the present disclosure is shown in fig. 4. The process cartridge 110 includes the photoconductor drum 10, the corona charger 52, the developing device 40, the transfer roller 80, and the cleaning device 90. Reference numeral 95 in fig. 4 denotes a recording paper.

(solar cell)

One embodiment of the photoelectric conversion device of the present disclosure is a solar cell.

The solar cell includes a support, a sensitizing dye electrode layer comprising an organic sensitizing dye, and a ceramic membrane on the sensitizing dye electrode layer. The solar cell further includes a first electrode, a hole blocking layer, and a second electrode. The solar cell may further include other components as necessary.

One example of the photoelectric conversion device is a solar cell hereinafter. However, the photoelectric conversion device is not limited to a solar cell, and may also be applied to other photoelectric conversion devices.

A solar cell (photoelectric conversion device) according to the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to the embodiments described below, and may be changed within a range that can be achieved by those skilled in the art, such as other embodiments, additions, modifications, and deletions. Any embodiment is included in the scope of the present disclosure as long as the embodiment exhibits the functions and effects of the present disclosure.

A solar cell (photoelectric conversion device) includes a substrate serving as a support, a first electrode, a hole blocking layer, an electron transport layer, a sensitized dye electrode layer, a ceramic semiconductor film serving as a ceramic film, and a second electrode.

The structure of the photoelectric conversion device 10B as a solar cell will be described based on fig. 6. Note that fig. 6 is a cross-sectional view showing one example of a solar cell.

The embodiment shown in fig. 6 depicts a structure in which a first electrode 2 is formed on a substrate 1 serving as a carrier, a hole blocking layer 3 is formed on the first electrode 2, an electron transport layer 4 is formed on the hole blocking layer 3, a photosensitive material 5 is adsorbed on the electron transport material of the electron transport layer 4, and a ceramic semiconductor 6 is sandwiched between the first electrode 2 and a second electrode 7 facing the first electrode 2. Further, fig. 6 shows a structure in which leads 8 and 9 are arranged in such a manner that the first electrode 2 and the second electrode 7 are electrically conductive.

Details thereof will be described hereinafter.

< Carrier (substrate) >

The substrate 1 as the carrier is not particularly limited, and any substrate known in the art may be used. The substrate 1 is preferably a substrate formed of a transparent material. Examples of the substrate include glass, transparent plastic plates, transparent plastic films, and inorganic transparent crystals.

< first electrode >

The first electrode 2 is not particularly limited as long as the first electrode 2 is formed of a conductive material transparent to visible light. As the first electrode 2, any known electrode commonly used for a photoelectric conversion element or a liquid crystal panel can be used.

Examples of the material of the first electrode include indium tin oxide (hereinafter, referred to as ITO), fluorine-doped tin oxide (hereinafter, referred to as FTO), antimony-doped tin oxide (hereinafter, referred to as ATO), indium zinc oxide, niobium titanium oxide, and graphene. The above-listed examples may be used alone, or two or more examples may be used in combination as a laminate.

The average thickness of the first electrode is preferably 5nm or more but 10 micrometers or less, and more preferably 50nm or more but 1 micrometer or less.

Further, the first electrode is preferably disposed on the substrate 1 formed of a material transparent to visible light so as to maintain a certain hardness. As the substrate, for example, glass, a transparent plastic plate, a transparent plastic film, or an inorganic transparent crystal can be used.

A known product in which the first electrode and the substrate are integrated may be used. Examples thereof include FTO-coated glass, ITO-coated glass, zinc oxide: aluminum-coated glass, FTO-coated transparent plastic films, and ITO-coated transparent plastic films.

Further, the integrated product may be a product in which transparent electrodes formed by doping tin oxide or indium oxide with cations or anions having different atomic values or metal electrodes having a structure permeable to light such as grids and stripes are arranged on a substrate such as a glass substrate.

The above listed examples can be used alone or in combination or in the state of a laminate.

Further, in order to reduce the resistance, a metal wire may be used in combination.

Examples of the material of the metal lead include metals such as aluminum, copper, silver, gold, platinum, and nickel. The metal leads are formed by disposing metal leads on the substrate via vapor deposition, sputtering, or crimping, followed by disposing ITO or FTO.

< hole-blocking layer >

The material for constituting the hole blocking layer 3 is not particularly limited as long as the material is transparent to visible light and is an electron transporting material. The material is particularly preferably titanium oxide.

The hole blocking layer is arranged for the purpose of preventing a decrease in electric power due to recombination of holes in the electrolyte with electrons on the surface of the electrode when the electrolyte is in contact with the electrode (so-called reverse electron transfer). The effect of the hole blocking layer 3 is particularly significant in a solid dye-sensitized solar cell. This is because the speed of recombination (reverse electron transfer) of holes of the hole transport material with electrons on the surface of the electrode is faster in the solid dye-sensitized solar cell using the organic hole transport material than in the wet dye-sensitized solar cell using the electrolytic solution.

The method for forming the hole-blocking layer is not limited. In order to suppress current loss due to indoor light, a high internal resistance is required, and therefore a film formation method is important. Typical examples thereof include a sol-gel method as a wet film forming method. According to the sol-gel method, the resulting film has a low density, and thus current loss cannot be sufficiently prevented. Therefore, a dry film formation method such as sputtering is more preferable. According to the dry film forming method, the obtained film density is sufficiently high, and thus current loss can be prevented.

The hole blocking layer is formed to prevent electrical contact between the first electrode 2 and the hole transport layer 6. The average thickness of the hole blocking layer is not particularly limited. The average thickness thereof is preferably 5nm or more but 1 μm or less. In the case of wet film formation, the average thickness thereof is more preferably 500nm or more but 700nm or less. In the case of dry film formation, the average thickness thereof is more preferably 10nm or more but 30nm or less.

< Electron transport layer >

The solar cell includes a porous electron transport layer 4 formed on the hole blocking layer 3, wherein the electron transport layer may be a single layer or multiple layers.

The electron transport layer is formed of an electron transport material. As the electron transporting material, semiconductor particles are particularly used.

In the case of a plurality of layers, dispersions each including semiconductor particles having mutually different particle diameters may be applied to form the plurality of layers, or coating layers each including a different type of semiconductor or having a different resin or additive component may be arranged to form the plurality of layers. Multilayer coating is an effective method when the average thickness of one coating layer is insufficient.

The light trapping rate is higher because the amount of the light-sensitive material carried per unit projected area increases with the average thickness of the electron transport layer. However, the diffusion length of the injected electrons increases, and thus the loss due to recombination of charges is large. Therefore, the average thickness of the electron transport layer is preferably 100nm or more but 100 μm or less.

The semiconductor is not particularly limited, and any semiconductor known in the art may be used. Specific examples of the semiconductor include a single semiconductor (e.g., silicon and germanium), a compound semiconductor (e.g., a chalcogenide compound of a metal), and a compound having a perovskite structure.

Examples of the chalcogenide compound of the metal include: oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium niobium or tantalum; sulfides of cadmium, zinc, lead, silver, antimony, or bismuth; selenides of cadmium or lead; and cadmium telluride.

Examples of the other compound semiconductors include: phosphides of zinc, gallium, indium, cadmium, and the like; gallium arsenide; copper indium selenide; and copper indium sulfide.

Further, the compound having a perovskite structure is preferably strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate.

Among the examples listed above, an oxide semiconductor is preferable, and titanium oxide, zinc oxide, tin oxide, and niobium oxide are preferable. The above listed examples may be used alone or in combination. The crystal type of the above semiconductor is not particularly limited, and the crystal type may be single crystal, polycrystalline, or amorphous.

The average particle diameter of the primary particles of the semiconductor particles is not particularly limited. The average particle diameter is preferably 1nm or more but 100nm or less, and more preferably 5nm or more but 50nm or less.

Further, by mixing or laminating semiconductor particles having an average particle diameter larger than the above average particle diameter, the effect of scattering incident light can be utilized to improve efficiency. In this case, the average particle diameter of the semiconductor particles is preferably 50nm or more but 500nm or less.

The production method of the electron transport layer is not particularly limited. Examples of the production method thereof include: a method of forming a thin film in vacuum, such as sputtering; and a wet film formation method.

In view of production cost, a wet film-forming method is particularly preferable, and a method of preparing a paste in which semiconductor particles or a sol are dispersed and applying the paste on an electrode substrate of an electronic current collector is preferable.

When a wet film-forming method is used, the coating method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the coating method include dip coating, spray coating, wire bar coating, spin coating, roll coating, blade coating, and gravure coating. Further, as the wet printing method, various methods such as relief printing, offset printing, gravure printing, intaglio printing, rubber plate printing, screen printing, and the like can be used.

In the case where the dispersion of the semiconductor particles is produced by mechanical pulverization or using a mill, the dispersion is formed by dispersing at least the individual semiconductor particles or a mixture of the semiconductor particles and the resin in water or an organic solvent. Examples of the resin used include polymers or copolymers of vinyl compounds (e.g., styrene, vinyl acetate, acrylic esters, and methacrylic esters), silicone resins, phenoxy resins, polysulfone resins, polyvinyl butyral resins, polyvinyl formal resins, polyester resins, cellulose ester resins, cellulose ether resins, polyurethane resins, phenol resins, epoxy resins, polycarbonate resins, polyarylate resins, polyamide resins, and polyimide resins.

Examples of the solvent in which the semiconductor particles are dispersed include water, alcohol-based solvents (e.g., methanol, ethanol, isopropanol, and α -terpineol), ketone-based solvents (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone), ester-based solvents (e.g., ethyl formate, ethyl acetate, and N-butyl acetate), ether-based solvents (e.g., diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane), amide-based solvents (e.g., N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone), halogenated hydrocarbon solvents (e.g., dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene), and hydrocarbon-based solvents (e.g., n-pentane, n-hexane, n-octane, 1, 5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene). The above-listed examples may be used alone or in combination as a mixed solvent.

An acid (e.g., hydrochloric acid, nitric acid, and acetic acid), a surfactant (e.g., polyoxyethylene (10) octylphenyl ether), or a chelating agent (e.g., acetylacetone, 2-aminoethanol, and ethylenediamine) may be added to a dispersion of semiconductor particles or a paste of semiconductor particles obtained by a sol-gel method or the like in order to prevent reaggregation of the particles.

In addition, the addition of a thickener is also effective for improving film-forming properties. Examples of the thickener to be added include polymers (e.g., polyethylene glycol and polyvinyl alcohol) and thickeners (e.g., ethyl cellulose).

After the semiconductor particles are applied, the particles are brought into electrical contact with each other and are preferably subjected to firing, microwave radiation, electron beam radiation or laser radiation in order to improve film strength or adhesion to the substrate. The above listed treatments may be performed alone or in combination.

In the case where firing is performed, the range of the firing temperature is not particularly limited. Due to the too high temperature, the resistance of the substrate becomes too high or the substrate may melt. Therefore, the firing temperature is preferably 30 degrees celsius or more but 700 degrees celsius or less, and more preferably 100 degrees celsius or more but 600 degrees celsius or less. Further, the firing duration is not particularly limited. The firing duration is preferably 10 minutes or more but 10 hours or less.

The microwave irradiation may be performed by applying microwaves from the side in which the electron transport layer is formed or from the back side. The duration of irradiation is not particularly limited. The microwave irradiation is preferably carried out within 1 hour.

After firing, for example, in order to increase the surface area of the semiconductor particles or to improve the electron injection efficiency from the photosensitive material to the semiconductor particles, electroless plating may be performed using a mixed solution of an aqueous solution of titanium tetrachloride and an organic solvent, or electrochemical plating may be performed using an aqueous solution of titanium trichloride.

The films each having a diameter of several tens of nanometers, which are aggregated by firing the semiconductor particles, are formed in a porous state. Such nanoporous structures have extremely high surface area, and this surface area can be represented by a roughness factor.

The roughness factor is a value indicating the actual area within the hole relative to the area of the semiconductor particles applied on the substrate. Therefore, a larger roughness factor is more preferable. The roughness factor is related to the average thickness of the electron transport layer. In the present disclosure, the roughness factor is preferably 20 or more.

< electrode layer for sensitizing dye >

The solar cell includes a sensitized dye electrode layer formed by adsorbing an organic sensitized dye (photosensitive material) on the surface of an electron transport material as the electron transport layer 4.

Organic sensitizing dyes (photosensitive materials) -

The photosensitive material 5 as the organic sensitizing dye is not limited to the above as long as the photosensitive material is a compound that is excited by the excitation light. Specific examples of the photosensitive material include the following compounds.

Examples thereof include: metal complexes disclosed in Japanese examined patent application publication No. 07-500630 and Japanese unexamined patent application publication Nos. 10-233238, 2000-26487, 2000-323191 and 2001-59062; coumarin compounds disclosed in Japanese unexamined patent application publication Nos. 10-93118, 2002-164089 and 2004-95450 and J.Phys.chem.C,7224, Vol.111 (2007); polyene compounds disclosed in japanese unexamined patent application publication nos. 2004-95450 and chem.commun.,4887 (2007); indoline compounds disclosed in japanese unexamined patent application nos. 2003-; thiophene compounds disclosed in j.am.chem.soc.,16701, vol.128(2006) and j.am.chem.soc.,14256, vol.128 (2006); cyanine dyes disclosed in Japanese unexamined patent application publication Nos. 11-86916, 11-214730, 2000-106224, 2001-76773 and 2003-7359; merocyanine dyes disclosed in Japanese unexamined patent application publication Nos. 11-214731, 11-238905, 2001-52766, 2001-76775 and 2003-7360; 9-arylxanthene compounds disclosed in Japanese unexamined patent application publication Nos. 10-92477, 11-273754, 11-273755 and 2003-31273; triarylmethane compounds disclosed in Japanese unexamined patent application publication Nos. 10-93118 and 2003-31273; phthalocyanine compounds disclosed in Japanese unexamined patent application publication Nos. 09-199744, 10-233238, 11-204821 and 11-265738, J.Phys.chem.,2342, Vol.91(1987), J.Phys.chem.B,6272, Vol.97(1993), electroananal.chem., 31, Vol.537(2002), Japanese unexamined patent application publication Nos. 2006-032260, J.Porphyrins Phylocyanines, 230, Vol.3(1999) and Angew.chem.int.Ed.,373, Vol.46(2007), Langmuir,5436, Vol.24 (2008); and porphyrin compounds. Among the examples listed above, metal complexes, coumarin compounds, polyene compounds, indoline compounds and thiophene compounds are particularly preferably used.

More preferable examples thereof include a compound represented by the following structural formula (3), a compound represented by the following structural formula (4), and a compound represented by the following structural formula (5), which are available from MITSUBISHI PAPER MILLS LIMITED.

[ chemical formula 1]

As a method of adsorbing the photosensitive material 5 on the electron transport layer 4, a method in which an electron collector electrode including semiconductor particles is immersed in a solution or dispersion of the photosensitive material, or a method in which a solution or dispersion is applied so that the photosensitive material is adsorbed on the electron transport layer, is used.

In the former case, an immersion method, a dipping method, a roll method, or an air knife method may be used.

In the latter case, a wire bar method, a sliding hopper method, an extrusion method, a curtain method, a rotary method, or a spray method may be used.

In addition, carbon dioxide may be used for adsorption in supercritical fluids.

When the photosensitive material is adsorbed, a condensing agent may be used in combination.

The condensing agent may be a substance exhibiting a catalytic effect of physically or chemically binding the photosensitive compound on the surface of the electron transport compound, or a substance stoichiometrically causing the chemical equilibrium to move in an advantageous manner. In addition, thiols or hydroxy compounds may be added as condensation aids.

Examples of the solvent in which the photosensitive material is dissolved or dispersed include water, alcohol-based solvents (methanol, ethanol, and isopropanol), ketone-based solvents (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone), ester-based solvents (e.g., ethyl formate, ethyl acetate, and N-butyl acetate), ether-based solvents (e.g., diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, and dioxane), amide-based solvents (e.g., N-dimethylformamide, N-dimethylacetamide, and N-methyl-2-pyrrolidone), halogenated hydrocarbon-based solvents (e.g., dichloromethane, chloroform, bromoform, iodomethane, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, and 1-chloronaphthalene), and hydrocarbon-based solvents (e.g., N-pentane, N-hexane, N-xylene, iodobenzene, and 1-chloronaphthalene), N-octane, 1, 5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, and cumene). The above listed examples may be used alone or in combination as a mixture.

Furthermore, depending on the type of compound used, some photosensitive materials may function more efficiently if aggregation between particles of the compound is inhibited. Therefore, an aggregation inhibitor may be used in combination.

The aggregation inhibitor is preferably a steroid (e.g., cholic acid and chenodeoxycholic acid), a long-chain alkyl carboxylic acid or a long-chain alkyl phosphonic acid. The aggregation inhibitor is appropriately selected depending on the photosensitive material used.

The amount of the aggregation inhibitor added is preferably 0.01 parts by mass or more but 500 parts by mass or less, and more preferably 0.1 parts by mass or more but 100 parts by mass or less, with respect to 1 part by mass of the photosensitive material.

The temperature when the above-mentioned adsorption photosensitive material or the combination of the photosensitive material and the aggregation inhibitor is used is-50 degrees celsius or more but 200 degrees celsius or less. Furthermore, the adsorption can be carried out at rest or under stirring.

Examples of the method of performing the stirring include stirring and ultrasonic dispersion using a stirrer, a ball mill, a paint conditioner, a sand mill, an attritor or a disperser. The method is not limited to the examples listed above. The time required for adsorption is preferably 5 seconds or longer but 1,000 hours or less, more preferably 10 seconds or longer but 500 hours or less, and more preferably 1 minute or longer but 150 hours or less. Furthermore, the adsorption is preferably carried out in the dark.

< ceramic film >

As the production method of the ceramic film 6 and the ceramic film in the solar cell, the substances described in the ceramic film of the photoelectric conversion device of the present disclosure and the production methods thereof can be appropriately selected and applied.

< second electrode >

The second electrode is disposed after the ceramic film is formed.

In addition, as the second electrode, the same electrode as the first electrode can be generally used. In a structure in which strength and sealability are sufficiently ensured, the second electrode does not always need a carrier.

Specific examples of the material of the second electrode include: metals such as platinum, gold, silver, copper and aluminum; carbon-based compounds such as graphite, fullerene, carbon nanotube, and graphene; conductive metal oxides such as ITO, FTO, and ATO; and conductive polymers such as polythiophene and polyaniline.

The average thickness of the second electrode layer is not particularly limited. In addition, the above listed materials may be used alone or in combination.

The second electrode may be formed on the hole transport layer by an appropriate method such as coating, lamination, vapor deposition, CVD, bonding, and the like depending on the type of material or hole transport layer used.

In order to function as a photoelectric conversion device (photoelectric conversion element), the first electrode or the second electrode, or both the first electrode and the second electrode are substantially transparent.

In the present disclosure, it is preferable that the first electrode side of the photoelectric conversion device is transparent, and the incident light enters from the side of the first electrode side. In this case, a material that reflects light is preferably used on one side of the second electrode, and the material is preferably glass or plastic or a metal thin film deposited with a metal or a conductive oxide by vapor deposition.

Further, it is effective to arrange the antireflection layer on the side on which sunlight is incident.

The photoelectric conversion element of the present disclosure is applied to a solar cell and a power supply device equipped with the solar cell. The application example is not limited as long as the product to be applied is a solar cell known in the art or a device using a power supply device equipped with a solar cell. For example, the photoelectric conversion element can be used as a solar cell for calculators and watches. One example of using the characteristics of the photoelectric conversion element of the present disclosure includes a power supply device of a mobile phone, an electronic notebook, or electronic paper. Further, the power supply device including the photoelectric conversion element of the present disclosure may also be used as an auxiliary power supply intended to extend the continuous usable time of an electric appliance that is chargeable or dry battery operated. Further, the photoelectric conversion element may be used as a primary battery optionally combined with a secondary battery as an independent power source of the sensor.

(organic electroluminescent element)

One embodiment of the photoelectric conversion apparatus of the present disclosure is an organic Electroluminescence (EL) element.

The organic EL element includes a conductive support, a charge transport layer including an organic charge transport material on the conductive support, and a ceramic film on the charge transport layer. In addition, the organic EL element further includes a positive electrode (first electrode), a hole transport layer, a light emitting layer, and a negative electrode (second electrode). The organic EL element may further include other layers such as a barrier film as necessary.

Note that a layer including a positive electrode (first electrode), a hole transporting layer, a light-emitting layer, an electron transporting layer as a charge transporting layer, and a negative electrode (second electrode) may be referred to as an "organic EL layer".

An example in which the photoelectric conversion device is an organic EL element will be described below. However, the photoelectric conversion apparatus is not limited to the organic EL element, and may be applied to other photoelectric conversion apparatuses.

Fig. 7 shows an organic EL element 10C, which is one embodiment of the photoelectric conversion apparatus of the present disclosure. An organic EL element is provided which includes a ceramic film disposed as an outermost surface layer of an organic EL layer. The organic EL element 10C includes a substrate 2 serving as a support, an organic EL layer 3, and a ceramic film 4.

Note that the present disclosure is not limited to the following embodiments, and may be changed within a range that can be achieved by those skilled in the art, such as other embodiments, additions, modifications, and deletions. Any embodiment is included in the scope of the present disclosure as long as the embodiment exhibits the functions and effects of the present disclosure.

< Carrier (substrate) >

The substrate 2 used as a carrier is an insulating substrate. The substrate 2 may be a plastic substrate or a film-like substrate.

The barrier film may be disposed on the major surface 2a of the substrate 2.

For example, the barrier film may be a film formed of silicon, oxygen, and carbon, or a film formed of silicon, oxygen, carbon, and nitrogen. Examples of the material of the barrier film include silicon oxide, silicon nitrate, and silicon oxynitride. The average thickness of the barrier film is preferably 100nm or more but 10 μm or less.

< organic EL layer >

The organic EL layer 3 includes a light-emitting layer, and is a functional portion contributing to light emission of the light-emitting layer according to a voltage applied between the positive electrode and the negative electrode, such as a carrier mobility and a combination of carriers. For example, the organic EL layer is formed by laminating a positive electrode, a hole transport layer, a light emitting layer, an electron transport layer, and a negative electrode in this order from the side of the support substrate 2. The organic EL layer 3 and the organic EL element 300 shown in fig. 1 are of a top emission type in which light is emitted from the side opposite to the substrate 2 side.

The organic EL layer 3 is not particularly limited and may be appropriately selected from organic EL elements known in the art according to the intended purpose.

A transparent electrode is arranged as a negative electrode.

The transparent electrode is made of, for example, SnO₂、In₂O₃ITO, IZO, ZnO, Al, etc. In the case where the transparent electrode is used as the negative electrode, it is preferable that the uppermost layer of the organic EL layer is an electron injection layer in view of electron injection efficiency. The transmittance of the transparent electrode for light having a wavelength of 400nm or longer but 800nm or shorter is preferably 50% or more, and more preferably 85% or more. The average thickness of the transparent electrode is preferably 50nm or more, more preferably 50nm or more but 1 micron or less, and more preferably 100nm or more but 300nm or less.

< ceramic film >

As the ceramic film 4 of the organic EL element and the method for producing the ceramic film, the ceramic film described in the present disclosure and the method for producing the same can be appropriately selected and applied.

The ceramic film 4 is disposed on the negative electrode in such a manner as to be embedded in the organic EL layer 3. The ceramic film 4 is disposed on the side of the organic EL layer 3 opposite to the side in which the substrate 2 is disposed. The ceramic membrane 4 has a gas barrier function, in particular a moisture barrier function.

Examples

The present disclosure will be described in more detail by way of the following examples and comparative examples. However, the present disclosure should not be construed as being limited to these embodiments. Note that "parts" described below means "parts by mass".

(example 1)

Production example of electrophotographic photoconductor

The electrophotographic photoconductor of example 1 was produced in such a manner that the intermediate layer, the charge generation layer, the charge transport layer, and the ceramic semiconductor film were arranged on the conductive support in this order as shown in fig. 5.

Formation of an intermediate layer

The following intermediate layer coating liquid was applied on a conductive support (outer diameter: 60mm) formed of aluminum by immersion to form an intermediate layer. After drying the interlayer at 170 degrees celsius for 30 minutes, the average thickness of the interlayer was 5 microns.

(intermediate layer coating layer)

Zinc oxide particles (MZ-300, available from TAYCA CORPORATION): 350 parts of

3, 5-di-tert-butylsalicylic acid (TCI-D1947, available from Tokyo Chemical Industry co., ltd.): 1.5 parts of

Blocked isocyanate (SUMIDUR (registered trademark) 3175, available from Sumitomo Bayer Urethane co., ltd., solids content: 75% by mass): 60 portions of

A solution obtained by dissolving 20% by mass of a butyral resin in 2-butanone (BM-1, available from SEKISUI CHEMICAL co., ltd.): 225 parts by weight

2-butanone: 365 parts of

Formation of a charge generation layer

The following charge generation layers were applied on the obtained intermediate layer by dipping to form a charge generation layer. The average thickness of the charge generation layer was 0.2 μm.

(Charge generation layer coating liquid)

Type Y oxytitanium phthalocyanine: 6 portions of

Butyral resin (S-LEC BX-1, available from SEKISUI CHEMICAL co., ltd.): 4 portions of

2-butanone (available from KANTO CHEMICAL co., inc.): 200 portions of

Formation of the charge transport layer 1

The following charge transport layer coating liquid 1 was applied on the obtained charge generation layer by dipping to form a charge transport layer 1.

After drying at 135 degrees celsius for 20 minutes, the average thickness of the charge transport layer was 22 microns.

(Charge transport layer coating liquid 1)

Bisphenol Z polycarbonate (PANLITE TS-2050, available from TEIJIN LIMITED): 10 portions of

A low molecular weight charge transport material represented by the following structural formula (6): 10 portions of

[ chemical formula 2]

Tetrahydrofuran: 80 portions

Formation of the ceramic film 1

(Pyrite)

Copper (I) oxide (available from Wako Pure Chemical Industries, ltd.): 40.014g

Alumina (AA-03, available from Sumitomo Chemical co., ltd.): 28.52g

A thin film of the above copper aluminum oxide (film thickness: 1 μm) was formed on quartz glass by the following method, thereby obtaining a sample.

Next, the obtained sample was set in an X-ray diffraction spectrometer (MiniFlex600, available from Rigaku Corporation) to measure an X-ray diffraction spectrum of copper aluminum oxide. Note that the measurement was performed by installing a detector D/te X Ultra2 in the X-ray diffraction spectrometer. The results are shown in fig. 9.

As shown in fig. 9, the X-ray diffraction spectrum of the copper aluminum oxide has a peak at a diffraction angle 2- θ of 31.5 degrees or more but 32.5 degrees or less, 35.5 degrees or more but 37.5 degrees or less, or 45.5 degrees or more but 47.5 degrees or less.

Further, a thin film having a film thickness of 1.7 μm was formed on the ITO glass using copper aluminum oxide by the following method. A gold counter electrode was arranged to the resultant by vacuum vapor deposition to thereby produce a sandwich-type cell.

The cell was set in a time-of-flight measurement apparatus (TOF-401, available from Sumitomo Heavy Industries, ltd. mechanics Division) to measure hole mobility. Specifically, the time-of-flight measuring device was set to apply a voltage of 34V to a sample having an average thickness of 1.7 μm to control the magnetic field strength within the sample to 2X 10⁵At V/cm, hole mobilityIs 1 × 10^-4cm²/Vsec。

Delafossite was prepared in the following manner. Copper (I) oxide and alumina were weighed and transferred to an empty mayonnaise bottle. The bottle was fixed on a sample stage of a shaker (VIBRAX-VXR Basic, available from IKA) and shaken at a shaking intensity of 1,500rpm for 1 hour, followed by heating at 1,100 degrees celsius for 24 hours, thereby obtaining copper aluminate. The obtained copper aluminate was ground by a motor to obtain delafossite powder having a number average particle diameter of 1 μm.

Used as the film forming chamber is an improved apparatus obtained by modifying a commercially available vapor deposition apparatus (VPC-400, available from ULVAC, inc.).

A commercially available stirrer (t.k. agi HOMO MIXER 2M-03, available from PRIMIX Corporation) was used as the aerosol generator. Note that a device in which a commercially available exhaust gas bottle (RBN-S, available from KSK co., ltd.) having a volume of 1L was arranged in an ultrasonic cleaner (SUS-103, available from Shimadzu Corporation) may also be used as the aerosol generator.

A tube having an inner diameter of 4mm was mounted from the aerosol generator to the film forming chamber and a nozzle (YB1/8MSSP37, available from Spraying Systems co.) was mounted at the edge of the tube. The photoconductor was disposed at a position 2mm from the nozzle. A movable carriage that can travel in the lateral direction is used as the photoconductor carriage. As the nozzle, a movable nozzle that can travel in the longitudinal direction is used. The film formation region can be determined by moving the photoconductor holder and the nozzle. Further, an aerosol generator was connected to a cylinder filled with nitrogen gas with a pipe having an inner diameter of 4 mm.

By the above apparatus, the ceramic film 1 having an average thickness of 1.0 μm was produced in the following manner.

The aerosol generator was charged with 40g of delafossite having a number average particle size of 1 micron. Next, the internal atmosphere from the film forming chamber to the aerosol generator was evacuated by an exhaust pump. Then, nitrogen gas was introduced from a gas cylinder into the aerosol generator and stirred to generate an aerosol in which particles were dispersed in nitrogen gas. The generated aerosol is ejected from the nozzle via a duct toward the photoconductor. The flow rate of nitrogen gas was set to a range of 13L/min or more but 20L/min or less. Further, the film formation duration was 20 minutes, and the degree of vacuum in the film forming chamber during the formation of the ceramic film 1 was set to an approximate range of 50Pa or more but 150Pa or less. Film formation is performed in a predetermined film formation region by moving the substrate holder and the nozzle.

The number average particle size of the delafossite was measured by analyzing an image obtained by a confocal microscope (optellics H-1200, available from Lasertec Corporation).

(example 2)

An electrophotographic photoconductor of example 2 was produced in the same manner as in example 1 except that the crosslinked surface layer 1 was formed instead of the ceramic film 1 in the following manner, and the ceramic film 1 was disposed and formed on the crosslinked surface layer 1.

Formation of a crosslinked surface layer 1

The following crosslinked surface layer coating liquid 1 was applied on the obtained charge transport layer by spraying in a nitrogen gas stream. The resultant was allowed to stand for 10 minutes in a nitrogen stream to allow contact.

The resultant was further dried at 130 ℃ for 20 minutes. The average thickness of the surface layer of the resulting crosslinked resin was 4.5 μm.

(crosslinked surface layer coating solution 1)

Bisphenol Z polycarbonate (PANLITE TS-2050, available as TEIJIN LIMITED): 75 portions of

Alumina (SUMICROREDUM AA03, available from Sumitomo Chemical Co., Ltd., average particle diameter: 300 nm): 25 portions of

Surfactant (BYK-P104, available from BYK): 0.5 portion

Tetrahydrofuran: 1,330 parts

Cyclohexanone: 570 parts (example 3)

An electrophotographic photoconductor of example 3 is produced in the same manner as in example 1 except that the crosslinked surface layer 2 is formed instead of the ceramic film 1 in the following manner, and the ceramic film 1 is disposed and formed on the crosslinked surface layer 2.

Formation of a crosslinked surface layer 2

The following crosslinked surface layer coating liquid 2 was applied on the obtained charge transport layer by spraying in a nitrogen gas stream. The resultant was allowed to stand for 10 minutes in a nitrogen stream to allow contact. Thereafter, light irradiation was performed in a UV irradiation chamber purged with nitrogen gas under the following conditions so that the oxygen content in the chamber was 2% or less.

(light irradiation conditions)

Metal halide lamp: 160W/cm

Radiation distance: 120mm

Radiation intensity: 700mW/cm²

Duration of irradiation: 60 seconds

(crosslinked surface layer coating solution 2)

Trimethylolpropane triacrylate (KAYARAD TMPTA, available from Nippon Kayaku co., ltd., acrylic equivalent: 99, trivalent or higher free radical polymerizable compound with no charge transport structure): 5 portions of

Dipentaerythritol caprolactone-modified hexaacrylate (KAYARAD DPCA-120, available from Nippon Kayaku co., ltd., acrylic equivalent: 324): 5 portions of

A radical polymerizable compound represented by the following structural formula (7) (monofunctional radical polymerizable compound having a charge transport structure, acrylic acid equivalent: 420): 10 portions of

[ chemical formula 3]

1-hydroxy-cyclohexyl-phenyl ketone (IRGACURE 184, available from Chiba Specialty Chemicals, photopolymerization initiator): 1 part of

Tetrahydrofuran: 100 portions of

(example 4)

An electrophotographic photoconductor of example 4 was produced in the same manner as in example 1 except that the charge transport layer 1 was replaced with a charge transport layer 2 produced in the following manner.

Formation of the charge transport layer 2

(Charge transport layer coating liquid 2)

Delafossite having a number average particle size of 1 micron: 68.534g

Silica (available from ULVAC, inc.): 68.534g

As the film forming chamber, a modified apparatus obtained by modifying a commercially available vapor deposition apparatus (VPC-400, available from ULVAC, Inc.).

A commercially available stirrer (t.k. agi HOMO MIXER 2M-03, available from PRIMIX Corporation) was used as the aerosol generator.

By the above apparatus, the charge transport layer 2 having an average thickness of 1.0 μm was produced in the following manner.

The charge transport layer coating liquid 2 was charged in the aerosol generator. Next, the internal atmosphere from the film forming chamber to the aerosol generator was evacuated by an exhaust pump. Then, nitrogen gas was introduced from a gas cylinder into the aerosol generator and stirred to generate an aerosol in which particles were dispersed in nitrogen gas. The generated aerosol is ejected from the nozzle via a duct toward the photoconductor. The flow rate of nitrogen gas was set to a range of 13L/min or more but 20L/min or less. Further, the film formation duration was 60 minutes, and the degree of vacuum in the film formation chamber during formation of the charge transport layer was set to an approximate range of 50Pa or more but 150Pa or less. Film formation is performed in a predetermined film formation region by moving the substrate holder and the nozzle.

(example 5)

An electrophotographic photoconductor of example 5 was produced in the same manner as in example 1 except that the ceramic film 1 was replaced with a ceramic film 2 in the following manner.

Formation of the ceramic film 2

A modified apparatus obtained by modifying a commercially available vapor deposition apparatus (VPC-400, available from ULVAC, inc.) was used as the layering chamber.

A tube having an internal diameter of 4mm was mounted from the aerosol generator to the lamination chamber and a nozzle (YB1/8MSSP37, available from Spraying Systems co.) was mounted at the edge of the tube. The photoconductor was disposed at a position 2mm from the nozzle. A movable carriage that can travel in the lateral direction is used as the photoconductor carriage. As the nozzle, a movable nozzle that can travel in the longitudinal direction is used. The delamination area can be determined by moving the photoconductor holder and the nozzle. Further, an aerosol generator was connected to a cylinder filled with nitrogen gas with a pipe having an inner diameter of 4 m.

By the above apparatus, the ceramic film 2 having an average thickness of 1.0 μm was produced in the following manner.

An aerosol generator was charged with 40g of alumina powder (available from Sumitomo Chemical co., ltd.) having a number average particle size of 1 micron. Next, the internal atmosphere from the film forming chamber to the aerosol generator was evacuated by an exhaust pump. Then, nitrogen gas was introduced from a gas cylinder into the aerosol generator and stirred to generate an aerosol in which particles were dispersed in nitrogen gas. The generated aerosol is ejected from the nozzle via a duct toward the photoconductor. The flow rate of nitrogen gas was set to a range of 13L/min or more but 20L/min or less. Further, the film formation duration is 20 minutes, and the degree of vacuum in the film forming chamber during the formation of the ceramic film 2 is set to an approximate range of 50Pa or more but 150Pa or less. Film formation is performed in a predetermined film formation region by moving the substrate holder and the nozzle.

The number average particle diameter of the alumina powder was measured by analyzing an image obtained by a confocal microscope (OPTELICS H-1200, available from Lasertec Corporation).

(comparative example 1)

An electrophotographic photoconductor of comparative example 1 was produced in the same manner as in example 1 except that the ceramic film 1 was replaced with the crosslinked surface layer 2.

(comparative example 2)

An electrophotographic photoconductor of comparative example 2 was produced in the same manner as in example 1 except that the ceramic film 1 was replaced with a protective layer produced in the following manner.

Formation of a protective layer

(protective layer coating liquid)

Bisphenol Z polycarbonate (PANLITE TS-2050, available from TEIJIN LIMITED): 100 portions of

Aluminum (Al) -doped zinc oxide (Pazet CK, available from HakusuiTech co., ltd., average particle diameter: 34 nm): 33.3 parts of

Surfactant (polymer of low molecular weight unsaturated polycarboxylic acid) (BYK-P105, available from BYK): 1.7 parts of

Tetrahydrofuran: 2,667 parts

Cyclohexanone: 667 parts by weight

Note that the protective layer coating liquid was prepared in the following manner.

First, in a 50mL container filled with 110g of zirconia beads (average particle diameter: 0.1mm), Al-doped zinc oxide, a surfactant and cyclohexanone were charged. The resultant mixture was vibrated and dispersed for 2 hours under a vibration condition of 1,500rpm, thereby preparing a dispersion liquid in which Al-doped zinc oxide was dispersed. Next, the dispersion was transferred to a 50mL vessel filled with 60g of zirconia beads (average particle diameter: 5mm), and dispersion was performed at a rotation speed of 200rpm for 24 hours, thereby preparing a millbase.

Then, the millbase was added to a tetrahydrofuran solution in which bisphenol Z polycarbonate was dissolved, thereby preparing a protective layer coating liquid having the composition listed above.

< evaluation of electrophotographic photoconductor >

The electrophotographic photoconductors of examples 1 to 5 and comparative examples 1 to 2 produced in the above-described manner were evaluated in the following manner. The evaluation results of each photoconductor are presented in table 1.

<<NO₂Post exposure image evaluation>>

First, an electrophotographic photoconductor is made to do with NO₂Standing in the atmosphere for a predetermined period of time to allow NO₂Adsorbed on the surface of the electrophotographic photoconductor. As the exposure condition, investigation of making NO on the adsorption sites near the surface of the electrophotographic photoconductor₂Adsorption saturation conditions. As a result, it was found that it is preferable to perform the exposure for 24 hours in a chamber whose concentration is controlled to 40 ppm. Thus, as the exposure condition, the atmosphere was set to have 40ppm of NO₂Atmosphere of concentration and exposure time was set to 24 hours.

For NO₂Post exposure image evaluation was performed using a modified product of Ricoh Pro C9110 (available from Ricoh Company Limited) modified in the following manner: the initial idle process at the output is eliminated, a Protoner black C9100 is used, and the following paper is used: a3 size copy Paper (POD gloss coating, available from Oji Paper co., ltd.).

As an output image, the evaluation pattern was continuously printed on 3 sheets of paper in halftone at a time after 0, 1,000, or 10,000 sheets were printed. Dot reproducibility of the output image on 3 sheets of paper was confirmed with the naked eye and under a microscope, and evaluated based on the following evaluation criteria.

(evaluation criteria)

A: the dot reproducibility of the output image on 3 sheets was not changed and there was no problem.

B: the dot reproducibility of the output image on 3 sheets slightly changed, but there was no problem in practical use.

C: there is a significant density difference in dot reproducibility of the output image on 3 sheets.

TABLE 1

From the results of Table 1, it was found that even in NO₂After the exposure, the electrophotographic photoconductors obtained in examples 1 to 5 can also obtain stable image quality. Therefore, the layer formed on the outermost surface of the electronic device of the present disclosure is found to be suitable for a photoconductor, and the photoconductor is a photoconductor having resistance to chemical hazards.

(example 6)

Production example of solar cells

Production of titanium oxide semiconductor electrodes

A dense hole-blocking layer 3 of titanium oxide was formed on an ITO-based glass substrate by reactive sputtering of oxygen using a target formed of metallic titanium.

The resultant was then ball milled with 3g of titanium oxide (P90, available from NIPPON AEROSIL co., ltd.), 0.2g of acetylacetone, 0.3g of a surfactant (polyoxyethylene octylphenyl ether, available from Wako Pure Chemical Industries, ltd.), 5.5g of water, and 1.0g of ethanol for 12 hours.

The obtained dispersion was added to 1.2g of polyethylene glycol (#20,000) to prepare a paste.

The paste was applied to the hole blocking layer in such a way that its average thickness was 1.5 microns. After drying the applied paste at room temperature, the paste was fired in air at 500 degrees celsius for 30 minutes, thereby forming the porous electron transport layer 4.

Production of dye-sensitized solar cells

The titanium oxide semiconductor electrode was immersed in an acetonitrile/t-butanol solution (volume ratio 1:1) containing 0.5mM of a compound represented by structural formula (5) (available from MITSUBISHI PAPER MILLS LIMITED) as an organic sensitizing dye, and the resultant was left in the dark for 1 hour to allow the organic sensitizing dye to be adsorbed, thereby forming a sensitizing dye electrode layer.

Production of ceramic semiconductor films

A modified apparatus obtained by modifying a commercially available vapor deposition apparatus (VPC-400, available from ULVAC, inc.) was used as the film forming chamber.

A tube having an inner diameter of 4mm was mounted from the aerosol generator to the film forming chamber and a nozzle (YB1/8MSSP37, available from Spraying Systems co.) was mounted at the edge of the tube. The dye-sensitized solar cell was disposed at a position 2mm from the nozzle. A movable carriage that can travel in the lateral direction is used as the carriage. As the nozzle, a movable nozzle that can travel in the longitudinal direction is used. The film formation region can be determined by moving the holder and the nozzle. Further, an aerosol generator was connected to a cylinder filled with nitrogen gas with a pipe having an inner diameter of 4 mm.

By the above apparatus, a ceramic semiconductor film having an average thickness of 1.0 μm was produced on a semiconductor electrode with an organic sensitizing dye.

The aerosol generator was loaded with 40g of alumina powder (available from Sumitomo Chemical co., ltd.) having a number average particle size of 1 micron. Next, the internal atmosphere from the film forming chamber to the aerosol generator was evacuated by an exhaust pump. Then, nitrogen gas was introduced from a gas cylinder into the aerosol generator and stirred to generate an aerosol in which particles were dispersed in nitrogen gas. The generated aerosol is ejected from the nozzle toward the semiconductor electrode via the duct. The flow rate of nitrogen gas was set to a range of 13L/min or more but 20L/min or less. Further, the film formation duration is 20 minutes, and the degree of vacuum in the film formation chamber during formation of the ceramic semiconductor film is set to an approximate range of 50Pa or more but 150Pa or less. The formation of the ceramic semiconductor film in a predetermined film formation region is performed by moving the substrate holder and the nozzle.

Silver was deposited on the ceramic semiconductor film by vacuum vapor deposition at a thickness of 100nm to produce a second electrode, thereby producing the solar cell of example 6.

(comparative example 3)

A solar cell of comparative example 3 was produced in the same manner as in example 6 except that the following production of a hole transport layer was performed instead of the production of a ceramic semiconductor film.

Production of hole transport layers-

An organic hole transport material represented by the following structural formula (8) (

compound name

2,2 ', 7,7 ' -tetrakis (N, N-di-p-methoxyphenylamino) -9,9 ' -spirobifluorene, product No. SHT-263 available from Merck KGaA): 95mmol (solid content: 14% by mass) was dissolved in a chlorobenzene solution. The prepared solution was applied to a semiconductor electrode with an organic sensitizing dye by spin coating, thereby forming a hole transport layer.

Silver was deposited on the hole transport layer by vacuum vapor deposition at a thickness of 100nm to produce a second electrode, thereby producing a solar cell of comparative example 3.

[ chemical formula 4]

< evaluation of dye-sensitized solar cell >

Radiation at 23 ℃ and 55% RH in a white LED (300lux, 75 uW/cm)²) After the following 24 hours, the dye-sensitized solar cells of example 6 and comparative example 3 obtained in the above manner were subjected to measurement of photoelectric conversion efficiency. Next, the dye-sensitized solar cell was stored in an environment of 30 degrees celsius and 90% RH for 1 month, followed by measurement of photoelectric conversion efficiency in the same manner as described above. The photoelectric conversion rate reduction rate x of the photoelectric conversion efficiency measured at 23 degrees celsius and 55% RH was determined by the following formula.

(formula)

(conversion lowering rate x) ═ photoelectric conversion rate after storage at 30 degrees celsius and 90% RH)/(photoelectric conversion rate at 23 degrees celsius and 55% RH)

A desk lamp CDS-90alpha (stable mode, available from Cosmotechno co., ltd.) is used as the white LED. The solar cell evaluation system As-510-PV03 (available from NF CORPORATION) was used As the evaluation device.

As a result, the solar cell produced in example 6 had a photoelectric conversion rate of 19.73% and a photoelectric conversion rate decrease rate x of 10% at 23 degrees celsius and 55% RH. The solar cell produced in comparative example 3 had a photoelectric conversion rate of 20.11% and a photoelectric conversion rate decrease rate x of 25% at 23 degrees celsius and 55% RH.

(example 7)

An organic EL element was produced according to example 1 of japanese unexamined patent application publication No. 2003-007473.

Specifically, SiO in the mixture₂Indium Tin Oxide (ITO) which was formed as a bottom layer on a glass substrate by sputtering to obtain a surface resistance of 15 ohm/square was used as a positive electrode. After sequentially washing with neutral detergent, oxygen-based detergent and isopropyl alcohol, the resultant was set in a vacuum vapor deposition apparatus, and the internal gas was exhausted until the degree of vacuum reached 1 × 10^-4Pa. The following compound HTM-1 was deposited in a thickness of 40nm as a hole transport layer, the following compound EM-1 was deposited in a thickness of 15nm as a light emitting layer, the following compound No.1 was deposited in a thickness of 20nm as a second electron transport layer, and an 8-hydroxyquinoline aluminum complex was deposited in a thickness of 30nm as a first electron transport layer, wherein the deposition of the above layers was sequentially performed by vapor deposition. Further, a mask was set on the substrate, and an anode alloy of Mg: Ag ═ 10:1 (vapor deposition rate ratio) was formed in a thickness of 200nm, thereby producing an EL element having a light emitting region of 2mm × 2 mm. Note that the vapor deposition was performed at a substrate temperature of room temperature.

[ chemical formula 5]

Production of ceramic semiconductor films

After the anode was formed, a ceramic semiconductor film was produced in a nitrogen atmosphere (inert atmosphere) in the following manner without being exposed to the atmosphere.

A tube having an inner diameter of 4mm was mounted from the aerosol generator to the film forming chamber and a nozzle (YB1/8MSSP37, available from Spraying Systems co.) was mounted at the edge of the tube. The organic EL element was disposed at a position 2mm from the nozzle. A movable carriage that can travel in the lateral direction is used as the carriage. As the nozzle, a movable nozzle that can travel in the longitudinal direction is used. The film formation region can be determined by moving the holder and the nozzle. Further, an aerosol generator was connected to a cylinder filled with nitrogen gas with a pipe having an inner diameter of 4 mm.

With the above apparatus, a ceramic semiconductor film having an average thickness of 1.0 μm was produced in the following manner.

The aerosol generator was loaded with 40g of zinc oxide particles (MZ-300, available from TAYCA CORPORATION). Next, the internal atmosphere from the film forming chamber to the aerosol generator was evacuated by an exhaust pump. Then, nitrogen gas was introduced from a gas cylinder to the aerosol generator, and stirring was performed to generate an aerosol in which particles were dispersed in nitrogen gas. The generated aerosol is ejected from the nozzle toward the organic EL element via the duct. The flow rate of nitrogen gas was set to a range of 13L/min or more but 20L/min or less. Further, the film formation duration is 20 minutes, and the degree of vacuum of the film formation chamber during formation of the ceramic semiconductor film is set to an approximate range of 50Pa or more but 150Pa or less. The formation of the ceramic semiconductor film in a predetermined film formation region is performed by moving the substrate holder and the nozzle.

(comparative example 4)

An organic EL element of comparative example 4 was produced in the same manner as in example 7 except that a ceramic semiconductor film was not formed, but an organic EL layer in which a positive electrode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and a negative electrode were disposed in this order on a substrate was formed.

< evaluation of organic EL element >

The organic EL elements of example 7 and comparative example 4 produced in the above-described manner were driven to measure their service lives.

The service life was evaluated by LT80 representing the time required from the start of driving until the luminance decreased to 80 when the luminance at the time of initial driving was determined to be 100. By using 10mA/cm²The organic EL element was driven at a constant current to measure the service life. The driving voltage was set to 10mA/cm when the organic EL element was used²Voltage at the time of constant current driving. Current efficiency is when luminance is 1000cd/m²(i.e., 1,000 nit).

As a result of the measurement, the service life (LT80) of the organic EL element of example 7 was 15 hours, and the service life (LT80) of the organic EL element of comparative example 4 was 1 hour.

List of reference marks

10: latent electrostatic image carrier (electrophotographic photoconductor)

10B: solar cell

10C: organic electroluminescent element

100A: image forming apparatus with a toner supply unit

100B: image forming apparatus with a toner supply unit

110: processing box

Claims

1. A photoelectric conversion device, comprising:

a carrier;

a charge transport layer comprising an organic charge transport material or a sensitizing dye electrode layer comprising an organic sensitizing dye, wherein the charge transport layer or the sensitizing dye electrode layer is disposed on the support; and

a ceramic membrane disposed on the charge transport layer or the sensitized dye electrode layer.

2. The photoelectric conversion device according to claim 1, wherein the ceramic film is a ceramic semiconductor film.

3. According to claim2 the photoelectric conversion device described in 2, wherein⁵The ceramic semiconductor film has a charge mobility of 1X 10 under a magnetic field strength of V/cm^-6cm²a/Vsec or greater.

4. The photoelectric conversion device according to claim 2 or 3, wherein the ceramic semiconductor film comprises delafossite.

5. The photoelectric conversion device according to claim 4, wherein an X-ray diffraction spectrum of the ceramic semiconductor film has a peak at a diffraction angle 2 θ of 31.5 degrees or more but 32.5 degrees or less, 35.5 degrees or more but 37.5 degrees or less, or 45.5 degrees or more but 47.5 degrees or less.

6. The photoelectric conversion device according to any one of claims 1 to 5, wherein the photoelectric conversion device is an electrophotographic photoconductor.

7. A process cartridge, comprising: the photoelectric conversion device according to claim 6.

8. An image forming apparatus, comprising: the photoelectric conversion device according to claim 6.

9. The photoelectric conversion device according to any one of claims 1 to 5, wherein the photoelectric conversion device is a solar cell.

10. The photoelectric conversion device according to any one of claims 1 to 5, wherein the photoelectric conversion device is an organic electroluminescent element.